1. Field of the Invention
The present invention relates to a method of manufacturing a thin film transistor (TFT) having a uniform characteristic, a TFT manufactured by using the method, a method of manufacturing an organic light-emitting display apparatus, and an organic light-emitting display apparatus manufactured by using the method of manufacturing the organic light-emitting display apparatus.
2. Description of the Related Art
In general, a thin film transistor (TFT) including a polycrystalline silicon layer is characterized by its excellent electron mobility and its ability to configure a complementary metal-oxide-semiconductor (CMOS) circuit, and thus the TFT is used in the switching device of a high-definition (HD) display panel, a projection panel requiring a high amount of light, or the like.
According to the related art, a TFT is manufactured in such a manner that an amorphous silicon layer is formed on a substrate, the amorphous silicon layer is crystallized as a polycrystalline silicon layer, and then the polycrystalline silicon layer is patterned to have a predetermined shape, so that a semiconductor layer is formed. Afterward, a gate insulating layer is formed so as to completely cover the semiconductor layer, and a gate electrode is formed on the gate insulating layer.
However, according to the related art, the crystallization process is performed while the amorphous silicon is exposed to the air. Also, in the process in which the polycrystalline silicon layer is patterned so as to have the predetermined shape, the polycrystalline silicon layer contacts photoresist (PR). In this regard, contamination may occur in the amorphous silicon layer or the polycrystalline silicon layer in the crystallization process and the patterning process so that the TFT does not exhibit a uniform characteristic but has a distribution of characteristics.